Driving Assist Control of Wheeled Inverted Pendulum Wheelchair Using an Active Seat-Slider

For wheeled inverted pendulum (WIP) wheelchairs, a rider operates it in a sitting posture and a weight-shifting motion is achieved by only rotating an upper-body around a waist. This causes a drop of acceleration and deceleration ability of the wheelchairs, as more, a rider feels anxious when the wheelchair inclines back and forth while accelerating and decelerating. To cope these issues, in this paper, a WIP wheelchair with an automatic CoG moving device and a braking system is proposed. The proposed WIP wheelchair has priority in reducing its tilt angle while accelerating and decelerating. This can be realized by automatically moving a rider with an implemented electric slider. The automatic-stop function is realized by controlling the slider so that the wheelchair can stop regardless of a joystick operation when a distance to an obstacle is closer than a predefined threshold distance. The effectiveness of the proposed driving assist functions were confirmed through accelerating experiments and an automatic-stop experiment.